Presentation Title

Effects of Timing and Magnitude of Waist Pulling Assistance on Metabolic Cost and Joint Mechanics

Advisor Information

Philippe Malcolm

Location

UNO Criss Library, Room 225

Presentation Type

Oral Presentation

Start Date

1-3-2019 9:30 AM

End Date

1-3-2019 9:45 AM

Abstract

During walking, the need to generate muscular forces creates a metabolic demand. Studies showed that a constant forward traction force applied at the waist can reduce metabolic cost. However, there is limited information about the effects of non-constant traction forces. The purpose of the current study was to investigate the effects of timing and magnitude of different forward force profiles on metabolic cost. We developed an attachment structure that allows applying forward force profiles from a cable-pulling robot. We developed a controller that applied 33 force profiles as a function of step time. We measured rates of oxygen consumption and carbon dioxide production. Steady-state metabolic cost for each condition was estimated using a method for estimating instantaneous metabolic cost. Preliminary results indicate that conditions with higher horizontal forces and longer assistance durations have higher reductions in metabolic cost, and timings that overlap with the deceleration phase of the center-of-mass increased metabolic cost. Determining the optimal assistance profiles from this study could guide the development of powered walkers and assistive rehabilitation devices.

This document is currently not available here.

COinS
 
Mar 1st, 9:30 AM Mar 1st, 9:45 AM

Effects of Timing and Magnitude of Waist Pulling Assistance on Metabolic Cost and Joint Mechanics

UNO Criss Library, Room 225

During walking, the need to generate muscular forces creates a metabolic demand. Studies showed that a constant forward traction force applied at the waist can reduce metabolic cost. However, there is limited information about the effects of non-constant traction forces. The purpose of the current study was to investigate the effects of timing and magnitude of different forward force profiles on metabolic cost. We developed an attachment structure that allows applying forward force profiles from a cable-pulling robot. We developed a controller that applied 33 force profiles as a function of step time. We measured rates of oxygen consumption and carbon dioxide production. Steady-state metabolic cost for each condition was estimated using a method for estimating instantaneous metabolic cost. Preliminary results indicate that conditions with higher horizontal forces and longer assistance durations have higher reductions in metabolic cost, and timings that overlap with the deceleration phase of the center-of-mass increased metabolic cost. Determining the optimal assistance profiles from this study could guide the development of powered walkers and assistive rehabilitation devices.